Nowadays, within the field of lighting systems, a wide range of different lighting devices able to arbitrarily reproduce light spectra exist, the spectra previously obtained by means of a separate light spectrum analyzer device (such as scientific-grade equipment) or other devices specifically designed by experts with enough knowledge about physics and engineering of light spectra.
There also exist lighting apparatus that include light sensors and light sources, the light sensors being focused to obtain properties (e.g. color coordinates or light levels) of the light emitted by the light sources for adjusting or calibrating said emitted light in order to finally match it to a given reference value.
Other types of lighting devices integrating light sensors and light sources are also known, said light sensors being used for detecting presence (of people, for example) and adapting the intensity of the light emitted by the light sources according to the result of said detection. For example, in some devices the intensity of the light is decreased in case of not detecting presence with the objective of saving electric energy.
For example, the US patent application US 2010/0007491 A1 describes an integrated image recognition and spectral detection device particularly suitable for monitoring settings of a light. The application also describes how to automatically control the settings of a light through image recognition and spectral detection of the light exiting the same lighting device, particularly how to automatically control changes in the color properties of the light in response to the image recognition. To do so, the device includes an image sensor array for recognizing images and motion, and a light filtering structure, that may be for example a Fabry-Perot resonator structure or an array of cut filtered glass, for detecting spectral components of received light.
However, the above mentioned lighting devices present some drawbacks related to the fact that they modify the emission of their light output by using either a pre-stored spectral parameter or a measure of a light property which is inaccurate for certain applications, due to the fact that they use filters or other structures, that are not accurate enough for obtaining detailed spectral properties of light. In other words, said lighting devices are not suitable for use in interactive lighting environments where spectral changes occur as a consequence of multiple reflections caused by, for example, moving objects found in the environment where the device is placed or changes in daylight conditions of the environment, and also, they are not able to react to said spectrum changes accordingly in real time.